Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Laboratório de Fisiologia Básica e da Cognição, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500, CEP 90050-170 Porto Alegre, RS, Brazil.
Hematology and Stem Cell Laboratory, Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, 2752, 90610-000 Porto Alegre, RS, Brazil; Instituto de Pesquisas com Células-tronco, Porto Alegre, RS, Brazil.
Neurobiol Learn Mem. 2019 Sep;163:107040. doi: 10.1016/j.nlm.2019.107040. Epub 2019 Jul 13.
Early life stress such as physical abuse, trauma or neglect during a critical period of development can elicit negative long-lasting effects on health. Neonatal maternal deprivation (MD) is a stressful event capable of triggering structural and neurobiological changes in Central Nervous System (CNS) development during proliferative and migratory cell differentiation. In this study, we investigated the maternal behavior of lactating rats submitted to protocol of chronic neonatal maternal deprivation (MD) during postnatal day (PND) 1 until 10. We analyzed the effects of the MD in the olfactory memory and cellular proliferation and differentiation in the hippocampus and olfactory bulb in Wistar rat pups on 7, 11 and 21 days postpartum. Analysis in active neurons, cellular differentiation and proliferation, were marked and evaluated by flow cytometry in tissue samples of hippocampi and olfactory bulb. Our results demonstrated an increase in maternal behavior immediately after dam's return to the home-cage in MD group compared to the non-deprived group. In addition, MD pups spent more time (higher latency) to identify the nest odor in comparison to the non-deprived rat pups in the olfactory learning task and showed a significant delay in the neural differentiation and proliferation in the hippocampus and olfactory bulb. These results reveal that disruptions in the mother-infant bonding by the MD induce changes in maternal behavior and interaction with the offspring that could be leading to delayed CNS development and significant impairment in offspring's olfactory learning.
早期生活压力，如在发育关键期遭受身体虐待、创伤或忽视，可能会对健康产生长期的负面影响。新生期母体剥夺（MD）是一种应激事件，能够在中枢神经系统（CNS）发育的增殖和迁移细胞分化过程中引发结构和神经生物学变化。在这项研究中，我们研究了哺乳期大鼠在产后第 1 天至第 10 天接受慢性新生期母体剥夺（MD）方案后的母性行为。我们分析了 MD 对 Wistar 幼鼠海马和嗅球嗅记忆、细胞增殖和分化的影响，分别在产后第 7、11 和 21 天。通过对海马和嗅球组织样本进行流式细胞术分析，对活跃神经元、细胞分化和增殖进行标记和评估。我们的结果表明，与未剥夺组相比，MD 组的母性行为在母鼠返回巢穴后立即增加。此外，与未剥夺的大鼠幼鼠相比，MD 幼鼠在嗅觉学习任务中识别巢气味的时间更长（潜伏期更高），并且在海马和嗅球中的神经分化和增殖方面表现出明显的延迟。这些结果表明，MD 导致母婴结合中断，从而改变母性行为和与幼鼠的相互作用，可能导致中枢神经系统发育延迟和幼鼠嗅觉学习能力显著受损。
